Love is when you are 100% comfortable in another person's company, longing to be with them, often, when distance is keeping you apart. You're incomplete without them, as they are without you and either party would happily make the ultimate sacrifice if it could help the other live.
Tantric sex is just the big fat cherry on the love cake?
You have to be in love with someone to truly love them, then (platonic relationships excepted, naturally)? Personally, I think the boundaries between being infatuated with someone and loving someone are a little blurred and open to interpretation.
You are right