The birthday boy for April 5 is Spencer Tracy.
In astrology, sun signs have very little to do with sexuality. If astrologers are attempting to make determinations about an individual’s sexual orientation in a natal chart, they usually look to Venus/Mars dynamics and some other significant planetary aspects and house positions.
Nevertheless, there are manly signs and girly signs. Aries is generally considered to be the most manly sign in the zodiac. So while I’m generalizing, I’ll admit that I don’t find it surprising that Spencer Tracy had an Aries sun. Has there ever been an actor who seemed more heterosexual? I can’t think of one.