For context: We picked this boys name for DD before finding out she was a girl and want to use it if we have a boy this time.
But about a year ago DHs sister started dating someone with the same name - and they're moving in together soon so presumably he plans to stick around. He's a lovely guy, but I don't know if he/SIL will be mortally offended if we stick with our plan to use the name.
To make it even more complicated, he is from abroad and the name is his 'English' name, not his real one, but everyone including SIL calls him by this.