[scaless]

My boyfriend and I have been seeing each other for about five months, and in the past three months he has been starting to see red spots on his penis after we have sex. They go away after a few days, and are painless, and we have both been tested for all STDs. I switched to a different soap and the problem went away, however I am beginning to think that the soap was only correlated with it in time, as the problem is periodically coming back. What could the causes be? This is causing a strain on our relationship, and I refuse to buy the "allergic" excuse.

[oxy-moron]

It is probably yeast/ fungal. He should be cleaning his penis after sex and this would stop the problem. He should be doing this anyway as guy maintenance.
You probably need to cut back on simple sugars in you diet as well and look at a pharmacy provided thrush cure.

[ilovhr]

You both should visit to doctor for infection checks.

[Texasred]

You both should visit to doctor for infection checks.

I believe she said they had done so.

[Colorado]

Could there be an overabundance of hair involved that is causing irritating friction burns/bumps?

[Guest]

Go see a physician together during one of his "flare ups". Seeing a physician when he's not "flared up" probably does little good.

STDs can come along any time, so unless you are being tested frequently, they can be missed....even in blood tests.