Potential risk aka how to prevent transmission with positive partner

[123Hector123]

Hi, few months I reported my partner (gay couple) became positive after accident (needle attack). I would like to ask few question.
1) in case my partner is undetectable in blood (on ART) and we use condom, is ther something to worry about?
2) our doctor warned us not to have oral sex (cause of potential residaul viruses on sperm) I actually start with PReP and after 3 weeks of taking pills is there something to worry about or is better to test viral load in his semen? (I have read and reread the only 3 ways of transmission and seems that even if he would not be threated there is no risk for me from oral sex.
3) any other advice how to prevent transmission?
4) in case of broken condom (he is threated and I take profylaxy, is there somethink to worry about (our doctor say not, but still more opinions is more opinions

Thank you for amswers

[AnxiousNoMore]

Since you read many times that oral is zero risk then you should know that is the case. We went over that last summer. And since you know the only 3, there is nothing else to know about method of transmission.