TL;DR
We are 3 people in a small room at our office. Me, Bob and Charles. I can smell Bob, but Charles said he didn't notice anything. Should I still report this to our manager/HR and let him handle it? Or should I just keep quiet and keep on opening my window every now and then?
Long story
Bob is our new trainee and joined us around 3 months ago. He has been on home office during the whole time, with occasionally coming back in to the office once a week or so. He always smelled a little bit sweaty, but nothing I couldnt bear for a day. But now that all of us are back in the office 5 days a week, I am distracted from work because of the strong smell. We've already had other trainees and interns the same age as he is over the past few years and it has never been that bad with any of them before.
I can already smell Bob when I enter the office, and after a week of "endurance" I thought about escalating this to HR, since it was especially bad today. But before complaining I wanted to know if I am not just being over-sensitive; if Charles had also noticed the bad odour I wouldve probably already written an email. But Charles said he never noticed anything! Not even today where it was especially bad. And that kind of set me back- I think he was being honest, and not just trying to defend Bob.
Do I still escalate this to HR? Do I wait for Charles to notice the odour, now that I brought his attention to it? Or do I try and live with it, since my smelling is probably (?) just hyper sensitive?
Update:
Talking to Bob directly is not an option, because I do not know Bob well enough to be able to tell how he would react - he might be professional about it or (worst case) he might overreact and report me for harassment. And no matter how he takes it, it would damage our working relationship, which is why this is not a question on how to talk to him. If Bob and I got along very well then yes, I would definitely just talk to him about it, but this is not the case.
Please also note that talking to our manager will not damage Bob in any way; I know our manager well enough for that. And I will not leave out the fact that Charles does not have this problem, thus making this completely my issue.
Increasing ventilation is only possible by keeping the window next to me open. And even though this action triggers my allergy to pollen, it is still a very weather dependant solution. I cannot keep the windows open when it's cold or rainy outside or even when there is heavy traffic going on during rush hours (loud engine sounds, trucks, honking).