Per the Catechism of the Catholic Church, homosexual actions are intrinsically disordered. The homosexual ‘attraction’ however is not specifically sinful but can ‘cross’ into sin (just as heterosexual ‘attraction’ can cross into sin) depending on whether that ‘attraction’ is dwelt upon and ‘furthered’ improperly. Being ‘attracted’ to a man (or a woman) no matter one’s sexuality by ‘noticing’ is one thing. . .to start to get specific urges, to begin to picture oneself becoming ‘involved’ is where the ‘attraction’ crosses over and can segue into **impure thoughts **which ARE sinful.
A homosexual person (or a chaste unmarried heterosexual person) can thus be ‘attracted’ to another person without incurring sin if the ‘attraction’ is kept from becoming impure. This is difficult but possible if one asks for God’s assistance.