There are a lot of fun things to do in Bangkok, but anybody will get tired of shopping and visiting temples after a while and begin to look for other things to do. The good news is that the city offers a wider variety of things to do than you might think, including some that you might find surprising.
Let your host know that you would like to do something a little different and they will surely have a lot of recommendations for you. If you like being outdoors, a day out at the incredible natural area known as the lungs of Bangkok is a great idea. You'll be amazed by the beautiful sights and a great time. Other options might include a jungle visit, the best option for the most adventurous ones out there.