How would you react?

Been married about 2 years. 3 kids, 1 together, plus 1 on the way. I know I am hormonal and quick to jump to the worst so checking here to see how you'd respond.

Over the last 18mo, 2x times I've caught my husband in lies about other women he was "friends" with. Both times claimed it was only always platonic with each. Never hooked up, never wanted to, etc. I trusted him; I generally feel like males and females can be just friends with boundaries. One way or another I found out with one he'd vent to her about our issues (not really ok with that but that's a separate issue) but never told her the good stuff so she was supportive of him ending the relationship. With the other I found out he did previously have a sexual attraction to her and they spoke openly about their individual sex lives with each other in detail. When confronted, he apologized, ceased all contact with them, and we moved forward. Few months later I found out he'd been masturbating to porn in secret. I do not have issues with that part. The problem was he swore up and down he rather wait for me, didn't jerk off anymore, and didn't have any interest in porn. It is less that he did it, more that he lied about it to my face for months.

These aren't huge issues like abuse or an outright affair and we worked through most or so I thought. Today I discovered there is one of his employees that he heart reacts every single message from her. All the messages were work related, but I noticed she is the only one he does that to. When asked about it, he said it is just an acknowledgement that he read it, but couldn't tell me why it was only to her messages and not all of his 50+ employees. I don't know how to feel or what to do. His history of lies with women makes me very edgy. Is it harmless? Am I overthinking this? Like I said, not affairs (at least that I know of) so not grounds to immediately pack the kids up and go, but idk what to do from here. Opinions?