Okay i totally walked in on my mom and stepdad! ewww please help?

okay i walked in on my mom and step dad having and i ran back to my room and i could hear my mom like groaning and stuff and ewww! its just not like my mom! im so grossed out but i allready know my step dad is all for so should i text him and be like "i so heard you guys last night" or not? because i kinda want them to know but im not gonna let them kno im completley and utterly freaked out! BTW: im 13 : /