I commented on a similar thread yesterday but decided to just start my own as I need clarity.
My partner has a female work friend and hasn't know her very long - I'd say 6 months. I've never met her. Within the last two months, they've started talking loads in the evenings (every day I think) either by text (back and forth for hours sometimes) Instagram (sending each other reels) or phone calls while playing a video game together. At first I thought nothing of it - he talks to loads of mates while playing video games while I'm in the room doing my own thing. The phone is always on loudspeaker and I can hear that the conversation is innocent.
But recently he's started to choose playing/talk to her for hours at a time instead of spending the evening with me. He continues talking to her after I've gone to bed. I heard them come off the game at 11pm the other night (on a work night) and continue their phone call for another half an hour. They don't only talk about the game, they talk about anything and everything. I heard her say something like 'I do enjoy your shoulder rubs though' so what? He gives her shoulder rubs? Is this normal?
He went to her house the other day for two hours, alone. He said it was innocent and I believed him but now I'm just questioning things.