Your GF comes over and instantly picks a fight with you about what you've been doing online. You head to your sisters room to blow off steam. She's annoyed you barged in but instantly knows something is wrong. You ask if it's alright to stay in her room tonight and of course she agrees. Your GF might not like it, but your sister doesn't care. You hop in bed with her and she offers to pull her soft tits out and nurse you to help you calm down (it's something you two used to do years ago) you know you shouldn't, but you can't resist her welcoming titties. You've never been good at saying no to your her so when she begs for your cock you let her climb on top and ride you even with your GF in the next room over.