One evening, my colleague and I were messing around. He was gluing things to the manager's desk and told me to glue something as well, so I did.
The next day, we were putting the blame on each other (jokingly) to the manager and I said 'I'm innocent, he told me to do it'.
Then my colleague said, "If I told you to suck me off would you?"
I just smiled and didn't say anything (it took me a second to register what he said) and the manager sort of smiled in shock and looked down awkwardly.
I don't know if he was trying to offend me of he was ignorantly joking. Should I have said something?
Another time, they were trying to get me to open a present in front of them, but I was embarrassed so didn't. My colleague kept telling me to, then said, "You're with two boys". I replied, "huh?", then he quickly said "James is your boss, so you have to open it".
Why would he say this, and how should I have reacted?