From my own experience, the tarot mostly works like a compass and will help you decode the current energy at play.
I like to use several decks and clarifier too because cards can have several meanings, and when you overlay them it gives you a better understanding of the initial energy picked up.
Now to answer more specifically your question. It looks to me that when you place X first, the energy that pops up is what is defined by his views / his side / his situation - while when you place yourself first, it shows the energy at play for you.
The lovers is not specifically a "positive" card - It may ask you to make a clear choice and to really question who you want to bind yourself to and why and ask if you are truly ready for that (The lovers is very similar than the Devil btw - so there is a fine line between a healthy and an unhealthy bound)
On his side he gets the queen of wands in the reverse... Is he involved with someone else? In this position she can represent a third party interference or the rival.
That's quite a big difference for a slight alteration to your question! I have no idea why this happens however I'm told by Golden Dawn Tarot who in my opinion is the best damn tarot reader out there that it does happen and wording is crucial. I have yet to learn how to phrase the question since she usually helps me out. I hate to enable a reading but if you're really interested in finding out from a pro if you don't get any responses here maybe you could call GDT for a few minutes? She's pretty affordable and would probably be happy to chat about it.
Thanks Greekgeek! I’m trying to stay away from readings but indeed this is so weird. It’s not even that one time. I tried asking the two questions again later in the day and got polar opposite answers. I wonder if it’s just not for me to know at this time.