i don't think it's "common" in japan, but there were a number of dudes making national headlines cause they had one legal and then one or more common-law wifes. so he prolly doesn't give a fuck.
I think Wakou is referring to Ayase's breasts touching him (当たったてます) instead of guessing the situation right since Ayase is letting her breasts touch him on purpose (当ててるんですよ).
The plot keeps being ridiculous as per usual.
At least we get to bear witness to a rare phenomenon called "communication" - almost unheard of in the realm of manga - allowing Wakou to overcome his uncertainty... Thanks for the chapter!