The OP is almost certainly not going to have a problem over such a circumstance, so it is indeed no big deal generally speaking. Travel in such a way is very routine.
Originally Posted by
cbn42
I don't think it's a big deal. No airline employee is going to think that your last name is "MR".
However, some actually do think just that, no less so because one of the more common names -- first, middle or last -- in some of the most populous countries in the world is "MIR".