would you be pissed if.....

Lately I've been noticing here and here that my husband is getting texts from "bri". I haven't thought anything of it because his cousin is married to a bri and I know that they talk. Well here it is 10:20 and his phone is being blown up by "bri". Which is unusual at this point. I ask babe? Who's texting you this late? He replies with "people from work being stupid". So now I'm like ok... he works with a bri? He doesn't know that I've been noticing this bri person popping up on his phone. So I feel like he's lying. Up to this point I've never had reason to not trust him but I just feel this is kinda weird. I tried to glance over his shoulder but of course he tilts his phone just right and I can't make out the words but whatever they are talking about he is typing a lot and so is "bri". I see lots of emojis too. Now, my husband barely texts me and never uses emojis so again... my antenna is going up. How should I approach this? I don't know how to start the conversation with him.