The ones that get us are tyoically single males with a screen name that references it being a couples profile at some time in the past. The optics just aren't good and immediately raises red flags.
Less than ideal online names
Not a profile name but there used to be a shipping company in my area called " south east express". The web address on the trucks was " SEXPRESS".
I always wondered how many calls they got asking what a sex press was.
So, yes, you do have to pay attention when choosing names.
We wanted to keep our name short and sweet after we had much longer hard to remember name.
A SBM on another site had the profile name of "Black the Rapist" so I assumed he was some sort of dom or something (not for us) and never even looked at the profile. At some point however after reading a forum post he made or perhaps a cert he had given I looked. He was into giving massages and his profile name was intended to be read as "Black Therapist".
PS - The actual profile name was all one word with no caps (blacktherapist) and this reflects only how I personally interpreted it. We even had an few email exchanges later and he seems like a nice guy. He has since changed the name to something else.
Ugh.
There's one profile I've seen which really makes my eyes boggle. It's named after a staggeringly depressing Meryl Streep film, where her character is sent to Auschwitz and is forced to choose which of her children is to go to the children's camp and which is to be gassed immediately.
Damn, have they even SEEN the film?????
We've all seen the common ones. For example, when someone first starts off they create an online name like "NewXXXXXX". At some point, you are no longer new but it has become part of your online name.
There are other cases where I just look and shake my head. For example, on another site I saw one as "whatCanUoffer". Maybe it's just me, but it just comes across as entitled and, even though they are close by and in our age range, just not someone I would reach out to. Anyone else have examples of names that, for whatever reason, rub them the wrong way?

