@Scp-3125  

 
The ring itself was forged to be a ridiculously expensive/rare item even BEFORE it was enchanted/cursed; never ment to be used by “peasants”, much less individuals of the same sex [who were not even allowed to “marry” back in the times when Grogar was still a “famous historical figure of the recent modernity”].
 
If the real reason for (at least one of them) to marry was to gain political power or money, then both (plus all in close proximity at the event, hence likely including anypony “involved” in the setup/scheme for it) will “pay the full price” for it in some way or another [whenever the ring can not be taken out].  
If instead it was from mutual, genuine love & desire to share a life together, then it only represented “a challenge” to overcome [including, yes… figuring it out in the middle of a sudden “zombie horde”]. No pain, no gain.
 
While the original inception for the enchantment+curse combo was ment to be just “pure punishment” with both effects going simultaneously (the ring “stuck” until death/amputation); a later adition of a partial self_supressing effect for the “curse” component [that also made it imposible to be detected by an “identification” spell, showing only the enchantment spell part], now allows the one wearing it to keep/recover their real identity.

@Argamis  
So basically it punishes the other individual if they aren’t bisexual, talk about an unfair test

@Scp-3125  

 
Why not both?  
. As soon as Lyra realized Bonbon´s ring must be enchanted with a “Wanted, Needed” spell; she took it out from her.  
-> THEN is when the hidden curse effect was revealed [it transforms Bonbon into a stallion whenever she is NOT wearing the cursed ring].
 
Only somepony who feels True Love for the wearer would not be affected by the “Wanted, Needed” Spell [since they already “do” in a natural way]; being able to take out the ring willingly, since the wearer can not do it themselves (everypony else is obsessed with “having the wearer”, not the ring).
 
The ring became a “TEST” ment for the typical heterosexual prince+princess couple (there is no “reversal” or “cure”, other than keeping wearing the ring with its active Wanted Needed Spell).  
The only “right answer” being for each one to wear once the ring, with the other one taking it out (only posible if both felt True Love for each others regardless of their current sex).  
If any of them was dishonest with their previously “professed love”, both of them [plus everypony else “involved” in the ceremony] will suffer the consequences in some way or another.
 
-> In the case of Lyra & Bonbon… they can at least take turns on getting back to their “old shape” to have some fun [as long as they make sure to be in a secluded place].

“By the power invested in me as Mayor, I now commandeer this already wed wife for my own lewd purposes! You may all kiss my ass in jealousy!”

@Background Pony #321A  
Bon Bon’s can be seen

I don’t think I see any panties in this image…

C’mon, Toon, that little addition in the description needs to be in the actual image xD .

This is canon and you can’t change my mind.

Huh, I would’ve thought that the ring would turn her into a stallion

Looks like she has to abandon her dress.  
It’ll be an embarrassing escape when she has to settle with just wearing panties; doesn’t look like she’s wearing a bra under that dress.

Poor dress.

ZOMBIES…..!!!!!!

@Amateur-draw  
Me too, the dresses are both adorable in their own way

@Setsugekka  
I agree on that. I like both wedding dresses.

What a waste of a good wedding dress. Come on Lyra, save your wife.

Who cast a “want it, need it” spell on Bon in the first place? And why?

same

Bont it, need it.

delightful, Lyra’s perfect wedding