I think in most cases, you may just be better off acting like they were the original recipient and not saying it was an accidental send.Source: What if the invite is for a big event or something super specific?
I told him I felt uncomfortble doing it and that I dont know what he wants and expects and all he's said is to grow up and act 20 andf to stop being a baby.
I feel like im failing him as a girlfriend and should just get over it and do it but I cant i dont know why but I cant and he doesnt seem to understand is it wrong I dont want to send him graphic text messages?
Personally, I probably still wouldn't say anything because I'd feel bad taking back the invite.
That said, I also don't think it's out of line to explain that the concert you just invited your lab partner to was actually meant to be a present for your BFF's birthday. It's awkward, but I think people would understand if you explain the miscommunication with the invite.
Still do it ASAP, and maybe see if that person wants to do something together in the future so they don't feel abandoned.