The meaning of tantra is the weaving of energy and tantric sex is a slow type of passion which creates a mind and body connection to culminate in an explosive ending of breath-taking bliss.
Sex is emotional, spontaneous and physical; it is the opposite of logic. If you have trouble reaching climax consistently then meditation can really help.
Here's a easy way to use meditation to give yourself calm and peace as well as bring harmony to your relationship. Isn't it worth less than an hour a day?