Sexual activity with a new casual partner always has some risk but there are things you can do to reduce your risk for any infection.  Several STIs can be reliably prevented through vaccination so this is something I would suggest you consider.  Depending on your age it is relatively likely that you are already vaccinated for Hepatitis B.  If you are not, you should be.  In addition both HPV and Mpox (the new term for Monkey Pox) is readily available, safe, and highly effective,  Consider them.

Second, as you approach new partners and as you did with this one, discussing their sexual history is always a good idea and is to be encouraged.  Appropriate questions are have you ever had an STI and if yes, when (persons who have had STIs before are more likely to get them again and the more recently a partner has had an STI, the higher the risk that they may have been re-infected).  A second good question is when were you last tested and for what (the more recently a person has been tested the less likely it is that they will have acquired an STI in the interval).  Having an STI in the past is not necessarily a bad thing but it helps provide perspective

The risk for other STIs is a function of sites of exposure and numbers.  Most STIs are transmitted by persons who are unaware that they have STIs.  ORal sex (performing or receiving) is a lower risk activity with other men that anal sex.  STIs are less efficiently transmitted (in the biological sense) through oral sex than through ano-rectal intercourse.  Obviously more partners increases risk.

Getting past these generalizations,  the encounter you describe sounds relatively low risk.  Your partner sounds to be relatively lower risk and you had the discussion you mentioned.  Even if a partner was infected, most single exposure do not lead to transmission.  In the absence of lesions, syphilis is unlikely.  Gonorrhea is typically symptomatic at the penis so your examination also suggests he was not infected.  

You may wish to get tested for your own peace of mind or, periodically if you will be having other partners in the future.  With fellatio the important test is a throat swab for gonorrhea (typically chlamydia is automatically done at the same time but is very, very rare at the throat).  A throat swab for gonorrhea can be done any time more than 3-4 days after your encounter.  If you wish to test for syphilis, you will need a blood test at 4-6 weeks after the encounter.  Your risk for syphilis from your report is low.  As for HPV, there is no test.

I hope this information and perspective is helpful.  If any part of this message (which may be more than you asked for) is unclear or there are other brief questions please use your up to two follow-up for clarification. EWH

However, in regards to monkey pox, syphilis, gono, etc... Am I free to live in a house with other people? I feel like testing, which is a personal choice, is most likely not warranted at this time?  Let me know your thoughts on regarding returning to normal live. Btw, exposure occurred to hours or so ago

In regards to Mpox, I checked the state dashboard again: 4 new cases in 2 months, but my county has only ever had 4 cases since beginning of that outbreak. 

Questions 

1)I feel Mpox is such a slight risk that I need not be concerned with it due to this incident, would you agree?

2)should I consider HIV prep/prophylaxis out of an abundance of caution?

3) should I consider dicilomine to mitigate syph, gono, and Chlamydia? It's been less than 24 hours of exposure

4) what would you estimate the statistical risk factor to be to acquire mpox, hiv, syph, gono, Chlamydia, AND/OR herpes. 

I estimate your r for acquistion of any of these infections to be a very small fraction of 1%

As I believe you know, we provide up to three responses to each client's questions.  This is my 3rd response.  Thus this thread will be closed shortly without further responses.  I hope that the information I have provided has been helpful. EWH