First of all, you tamagotchi must be an adult to use it. ^_^
When you give your tamagotchi the love potion, 2 hearts will appear at either side of it's head.
If your tama connects with another adult tama - but a different gender, they will automatically fall in love, get married and have tama babies.
But if one or both of the tamas are already married, it won't work I'm afraid.
And remember, the love potion only lasts for a short period of time - so use it wisely! ^_^
-sk8er girl-