I played my hotel stay differently.
I was staying away for a week and booked a girl, and done the usual discreet stairwell meeting to avoid the card key systems and more importantly my work colleague, and worked a treat.
Decided to book the girl for a second visit whilst I was there, but asked if she was up for a little game / roleplay type thing, and if she would meet me outside the hotel, and made up a story about her being an old family friend, who had moved away a few years ago but wanted to meet up for some horizontal refreshment. The girl is half my age, and attractive etc, and was well up for this as an added feature to the booking. Nothing too elaborate to keep it simple.
At work the next day I mentioned the 'story' to my colleague to plant a seed and made my excuses for not eating together that eve.
Everything was place and all good, met the girl around the corner from the hotel, at the appointed time and walked in together, genuinemy having a laugh and a giggle, but typically my colleague was no where to be seen. If i'd not wanted to be noticed we would have been spotted.
Went to my room, done the deed (fantastic punt, review posted) and then walked her back to her car via reception, and still no sign of the colleague. Next morning it turns out they had decided to eat in their room, and despite being a smoker (them not me) didn't venture out for a smoke either.
So if you want to be avoided, in my experience, tell then youre meeting a fit young girl, (Who you would want to be seen with) and no one will notice you!
I'm both relieved and disappointed that the story didn't come to fruition, as would have been a giggle.