If you are separated, and you sort of are. Let him know you have no problem with him coming over when he can, just let you know before hand by a call or a text.
If you feel like you need a boundary on this.
I know that I did.
Experience is a brutal teacher, but you learn. My God, do you learn. - C.S. Lewis
Life is usually all about how you handle Plan B. - Jack3Beans
Listen without defending; Speak without offending - FaithinAK