When my ex was living here, he too snuck out once, lol! It was quite pathetic to witness. And quite stupid on his part as I have a huge sheep dog that barks when anyone comes to the driveway. Before ex even came in from the garage I was at the bottom of the stairs and watched him slink (literally) into his self-made dorm room.
I certainly don’t miss those days. It was so, so much easier when he left.
Regarding surfing the dating sites, it’s great you recognize that you are trying to distract yourself. One unsolicited suggestion I have is to think about what it is about doing that which makes you feel better.
It gets easier. We promise.
Me 41, H 47, M 15 yrs, S11, S13 BD 1: 11/4/14 we work on it; really I pretzel myself BD 2: 3/31/15 H goes down to "dorm room" 8/15: H back to MBR 10/15: H back in dorm room 1/18: H files, now divorced