White marks/tears?

Hi all, last night I was giving my boyfriend oral and I noticed that there were several white circular marks on his bellend. A few were white and some were tears or little splits in the skin like blisters. My boyfriend had not noticed them and says the caused him no pain at all, he couldn't even feel them so we then had sex and he came inside me as usual, no problems - in fact it was great sex! His shaft and everything else are absolutely fine it's just these marks around the tip. He's not had sex with anyone but me for two years so we're pretty sure it's not an STD, any ideas?