Let's go back to sun in Libra and Saturn in Sag, and pretend it's a day chart, and those are our significators. Just to try to keep some continuity, ok?
The sun is detrimented, and it's in Saturn's house. Saturn receives the sun by exaltation, and sun receives Saturn by triplicity.
Ok, that's a start.
Is there an aspect? We'll put Saturn at 10 Sag and sun at 8 Libra. Yes, they're sextile.
This gives Saturn the ability to do something for the sun, and the reception by triplicity makes the sun somewhat more open to that than it might otherwise be.
So who likes who? Well, the sun is applying, moving faster than Saturn, so we can adjudge that the sun is probably the fonder.
Forget geometry for a moment. If sun rules 1 and we find Saturn there, then Saturn may be the fonder - he is in the sun's house. If we found sun in 7, sun might be the fonder, as he's in Saturn's house.
Reception is willingness. Aspect is ability to act. Who loves the best (which is NOT the issue in most love horaries, the issue is will you get together), if it can be determined at all, is more determined by planetary application or house (opposed to sign) position. At least that's the way I've seen it work out.