AITA for training my ex's new girlfriend for months without telling him?

ok so i (34F) am a personal trainer and i've been divorced from Dan (36M) for two years, we share custody of our son Max (6). back in October a new client signed up under the name Brittany, paid for 12 sessions upfront, $840, normal stuff. she was sweet, showing up 3x a week, actually crushing her goals. took me almost 6 weeks to clock that Brittany was THE Brittany, the one Dan's been posting with on instagram. she never brought him up and honestly neither did i because our sessions were going great and i didn't want to make it weird or lose the money since things are tight since the divorce. it finally blew up last weekend when Max casually said at dinner that daddy's girlfriend "does the same workouts as mommy." Dan lost it, called me saying i've been "coaching the enemy" behind his back for months and that it's manipulative, like i was trying to get inside info on his relationship or mess with her head. Brittany also messaged me saying she feels used, like i knew the whole time and let her keep training with me anyway. my sister thinks i should've said something the second i realized who she was, gym or no gym. i think i run a business and it's not my job to vet clients based on who they're dating, i didn't lie, i just didn't offer info nobody asked for. now Dan's saying he doesn't trust me around Max's stuff either which feels like a huge jump.

#aita#family

anonymous ask · Aug 19, 2026 · 47 votes · 0 comments