Urmila ji,
After reading all the comments and replies in the thread, there should be many things clear to you by now:
Let me try to summarize the points .
OLD times :
1. Widow remarriage was difficult and jat community came forward to improve the conditions for their bahu-betis.
2. Latta odhana( widow remarriage) was only performed when the husband died in early years of marriage. And it could be either devar or jeth ( in case no devars ). and if the lady had kids of considerable age (say 14-15 yrs) than there is very less chance of latta oodhana.
3. It is not by choice ,,i was and is a matter of fate.
That is why i believe there was some relaxation in the relation of devar and bhabi and jija-sali.
New Times:
1. It is still the same in new times too.
2. But now a days people are trying to sensationalize the relation of devar bhabi--jija sali..
3. If the widowed lady doesn''t want to marry his deceased husbands brother, and want to marry some else or want to spend life alone ,it is solely her wish,( conditions are different)
Now taking the part of flirtation, it is in the eye of beholder.
If both want a healthy relation there can be no flirtation only majak.
The case you discussed, i think they are some kind of illiterate fellows better call them animals.
And Polygamy/Polyandry is still practiced in some specific parts and areas ,so it can''t be generalised for all people.
If a boy girl in college time can have a very open friendship ( still they are not flirting) ,,why not devar-bhabi/jija-sali can have that kind of friendship...??