You did not indicate the kind of lobster or its size. But I assume you meant a "chicken" lobster that is around 1 to 1/2 lbs. That is what you find in most stores today. You will need two lobsters, one for you and one for your girlfriend.
1. Get a pot large enough to hold both lobsters. If you do not own such a pot, don't try to cook lobster. Go to a Kitchen shop and ask for a pot big enough to cook 2 lobsters. You can use the pot to cook crab, shrimp, corn on the cob, soup, gumbo, etc. Don't buy a cheap thin aluminum pot. Buy something thick and heavy that you can hand down to your children and grandchildren.
2. Fill it 75% full with good clean water. Use bottled water if your tap water has chlorine. Put pot on high heat to boil the water.
3. Smash 3 large garlic cloves and thrown them into the water skin and all.
4. Chop the top section with leaves of a bunch of celery and throw it into the water with the garlic. The top portion is the stalks after the waist.
5. Add 3 TBs of salt and 3 Tbsof sugar to pot.
6. Cut a fresh lemon in half and throw it into the pot.
6. Once the water with all the ingredients come to boil, drop lobsters into water and set timer for 12 min. Cook for 12 min.
7. If eating right away, set table with clarified butter and dig in.
8. If you wat to eat them later that day or the next day, while the lobsters are cooking, fill a sink with cold water and ice cubes. When the timer goes off, take lobsters out of pot, and throw into sink until they are cold.
9. Once cold, take meat out of shell. Use for salads or sautéed in butter with herbs over pasta.
Chef Bob refdrbob@gmail.com