"My boyfriend's semen has lumps in it. Does this mean he could have an STI?"
My boyfriend's semen has lumps in it. It didn't used to be like that but lately it seems to have chunky bits in it.
Does this mean he could have an STI?
No. Lumpy semen isn't a symptom of an STI. It's normal for the consistency of semen to alter because it's affected by diet, the temperature, how healthy he is, how much he's drunk and a multitude of other factors.
Clumpy semen is actually healthy semen because it makes it sticky and more likely to stay high in the vagina, rather than it running straight out, increasing the chances of fertilisation.
So long as it's not accompanied by any pain on urination or discharge from his penis, he (and you) will be fine.