(Y/n) pov
You were at home on your bed. It was that time of the year again... you were in heat... you hated this time. Of course, you could always ask Sans as you both have been dating for a year or so without doing anything at all but you were stubborn. You thought you could handle this on your own...

The heat began to become too much for your body to handle. You pulled down your pants and panties and began to thrust your fingers in and out of your entrance, moaning loudly. "S-Sans~ your so big~ i-i'm gonna~" You release your cum on your panties, some of it getting on your bed. You thought you had satisfied your head until your core began to become hot again. You started to moan, forgetting that you invited sans around to hang out today.

Sans' pov
I knocked on (y/n) s door, expecting her to fly out any second and hug me. When she didn't come out, I got confused and nervous that something happened to her. My protective boyfriend mode came on as I entered the house and rushed upstairs to find my baby.

I heard noises coming from her room. Is... is that moaning? I couldn't be too sure... she could be getting hurt for all I knew. I slammed open the door, ready for a fight  when I saw (y/n) sat on her bed with a pillow covering her mouth, trying to stop her moans. Her other hand was in her pants, thrusting in and out of her. I realised she was in heat and that she never said anything. I stood there for a while, listening to her muffled moans.  I walked in the room and locked the door. If she was in heat, then I am going to help her. If she wants the help or not.

No-one pov
Sans walked over to (y/n) and pinned her to her bed. She jumped up startled, not knowing Sans was in he house with her.
"S-sans~" she moaned, not being able to control her moaning. "S-sansy... i-i'm in h-heat..~"
"I know." He said, caressing his girlfriend's cheek. "And I'm gonna help you..."
"W-wait sans! You don't have-" (y/n) was cut off by Sans crashing his lips against hers. He licked her bottom lip and she playfully denied. Sans growled and squeezed (y/n) ass making her gasp. Sans took this chance to shove his tongue inside her caverns.  She moaned into the kids, wanting so much more.

Sans moved away from her lips and began to attack her neck with loving bites, picks and nibbles, trying to find her sweet spot. As soon as he found it, (y/n) let out a loud moan. Sans smirked and started to abuse the spot with bites and licks. By now, (y/n) was moaning up a mess and kept pushing her boyfriend's head down to carry on. He bit a little too hard and drew blood from the spot with his fangs. Sans began to suck and lick the blood off the spot and (y/n) began thrusting upwards wanting more.

"Needy aren't we baby." Sans said as he brought his hands to the bottom of her shirt. "Don't worry... I'll give you what you want soon..." he ripped (y/n) s pants and shirt of and began to lick and bite her stomach. (Y/n) moaned like her life depended on it. She was enjoying this but her heat wanted more. She tries to push sans to her core with her hands only for them to be pinned over her head with magic. She growled and tried to get free.

"Heh. You really want me to go there already? I haven't even had any fun yet~" (y/n) growled on confusion at his words until she felt her bra and panties being ripped from her body.
Sans attacked her left breast, biting, flicking her nipple, licking, sucking. He played with her right before doing the exact same thing to the other breast. His girlfriend later underneath  him, moaning and begging for him to enter her.

Sans got bored of her breasts and took of his jacket, shirt and pants slowly. This was turning (y/n) on so much as she tried to go to Sans and dominate him. He crawled to her, tongue out and ready.

"Wet already huh? This heat must be bad." he said as he entered his tongue into her hard and fast. (Y/n) moaned and screamed Sans' name so loud that if anyone else was in the house, they would have heard for sure. He thrust his tongue in and out. When (y/n) was about to come, Sans piled his head away and entered two fingers into her . This sent (y/n) crazy and she cummed straight away. Sans chuckled as he bent down and licked  the gum off her core and the bed.

"Now your ready." He said as he pulled out his massive member. (Y/n) stared in shock. How was that supposed to fit. "Don't worry. I'll make it fit." Sans rubbed his member on her core to lube it up and then thrust into her, entering her fully. Sans moaned as (y/n) helped in pain. Sans showed no mercy as he began to thrust into his girlfriend, not letting her ajust. Soon pleasure overcame (y/n) as she started moaning also. They couple moaned so loud that the whole of snowdin must of heard them.

"SANSY! IM GONNA-"
"SAME BABY, JUST GO-"
the couple screamed each others names as Sans trusted as deep as he could inside (y/n) and cummed. This set (y/n) cumming as well as her walls milked Sans' member of all the cum he had. He eventually pulled out and led on his girlfriend, head on her breasts. (Y/n) closed her eyes and drifted off to sleep, knowing her heat was finally satisfied.

A/n well that's it for this lemon chapter. Please leave comments about what to write next time! U til next time my lovely sinners...
Peace out
- author-chan

(P.S. 1036 letters)