While teaching how should I give justice equally to both female and male students?

If you really can't change your actions, find a different profession.

You're aware of the issue - you admit you spend more time helping the females than the males. Find a way to equalize that problem. Be sure that you make your time available to all genders - use office hours, or clarify to all students how to get help from you. Look for the patterns where you realize that you cut off help from the men and continued to help the women - there's like an unconscious bias that you may be able to over come with a pattern.

Changing a pattern like this may not be easy - but it's what's rightfully expected.

Also ponder - why - why do you give women more time? Are you hoping for something more than a teacher/student relationship? Is something more pleasing about them? What's causing the problem, and can you reduce the factors that lead up to it?

I suppose the other alternative is to find a place where you teach only one gender. Then you don't treat your students unequally. Personally, that seems like taking a short cut.

Normally, the problem is the other way round.

For instance, one phenomenon is that I often found with male students is that they override/overrule/overtalk female ones. If that happens more than sporadically, I interrupt them and tell them to let the other student speak out (of course this cuts both ways). I mention this as a concrete example for a trigger/action based approach that works well to reduce imbalance. With this, I get good participation from the whole group.

You talk about "soft spots". Beware, this signals danger. Your student's gender should be strictly taboo for how you deal with them. It is absolutely essential that all your students feel equally respected. Is it that you give more time to females? Then actively allocate more time to males. Is it that you encourage females more? Balance this by introducing some competitive element (such as voting on responses, competitive problem solving); male students tend to like that (of course, I am generalising, it needs playing by ear). Intersperse your presentations with adventurous anecdotes of topic-relevant scientists.

Generally: make a point of addressing more of the neglected students. BTW, this does not only hold for gender, but also for preference by activity or ability. Activate less able, or less active students. If you do that well, you earned your badge as teacher.

Under no circumstance treat your teaching as a dating opportunity. It is not. Getting a jealous girlfriend might be an idea to help getting things under control - if you cannot do it yourself, it may be the way to delegate that job to her (and I am not yet entirely sure whether I am joking here).

Overcoming biases is extremely difficult. In order to reduce your bias, you need to identify when (not necessarily why) you give extra attention to the female students. Once you know when you give extra attention, you can work on being fairer. Some possibilities are:

• If you preferable schedule them for office hours, you can use a first-come first-serve sign-up system (online or paper based).
• If the bias is related to answering question after class, you could require students to make an orderly line and address people in order (i.e., take your choice out of it).
• For question in class, you can use a "clicker" device so that people get addressed in order (and not when you see them).
• If you spend more time on each question from females, you could either time your answers, or make sure you finish your answer with "does that answer your question"
• If you grade differently based on gender, you can use anonymous electronic submission.