This is a test of commonsense. Complete the next sentence:

How to stay faithful if your boyfriend is far away from you
Keep in touch.
Have contact with him through his phone, email, skype, etc. Contact him often, and make sure to tell him that you miss him, love him, are giving him good wishes, and so on.
This will remind you how sweet, nice, and/or caring he is. You wouldn't want to cheat on a good person.