I saw it long time ago, and it really is bothering me, that I can't remember what it is. I only remember two scenes from it:

Man goes into hotel room or similar place, can't remember. There's maid who offers him room services, blowjob being one of them. She tells the man to call, if he wants anything.

In the next scene same guy is having sex with the maid, but they are interrupted by someone. Can't really remember was there someone knocking on the door, or did someone just barge in. Well, the maid leaves from the room, and those two guys begin talk about something.

Oh, and the maid was wearing red dress.

I hope someone recognizes the movie, even though I remember almost nothing of it!

I remember the scenes as you describe, but not much else from the movie, so I can't place the movie name just yet.

The man, definitely was in a hotel room, I think in a small town or roadside motel in a hot/desert location. I'm pretty certain he was called in to wait for someone to contact him. Maybe for him to find/kill someone or to make some exchange.
The maid you mention was also the receptionist/manager - The scene was her showing him the room when she offered the extra services.

One extra scene I remember is that later, he was meeting with 2 people, possibly the motel bar, and half-complained to them that they 'dragged me (him) out here, to the middle of no-where, where there's nothing to do... except the maid'.

I thought the man was Fred Ward, except I can't see from his filmography which movie it would be.

Maybe this will help a bit.