Of course they can and do --- it's how homosexuals reproduce. They try to convert young males, boys and teens. Hello, everyone knows this ---- it's why people didn't want homosexual scout masters and why the Catholic priests were such a problem.
New homosexuals are recruited not born. Homosexuals know this, which is why they're so eager to get kids comfortable with homosexuality at an early age, while moral parents are still protecting their kids from sexualization. Every active homo has spent time trying to convince associates or friends that homosexuality is normal so that they can get a date.
If homosexuals really believed people are born homosexual, why has there been practically no effort (university research) to identify congenital causes of lesbianism? Why has there been practically no effort to study, even if to rule out, environmental factors leading to homosexuality (e.g. early childhood sexual trauma)? The last and the next study you see claiming evidence that homosexuals are born that way, it's blatant bullshit about male homosexuals.
You can tell what people really believe by how they act, not by what they claim.